There are some brute force methods to do this. Often government websites that report data have it on their websites. For example, my city lists new business licenses issued monthly.
I have a business that serves the construction industry. California has a searchable database of all construction contractors that have ever signed up to bid of public works projects. The data includes contact info with name, phone and email, and not of just the business but of a responsible contact for the state to reach. The contacts are sequential via some Id# in the URL. When you're looking at the link, you can modify the link by hand by jumping 10000 ids forward and seeing if it's valid or not. Quickly you narrow down where the last ID is. Check it again next month, and you'll have all the new applicants. This is a very specific example, and not all websites work the same, but you may get lucky with an easy to 'scrape' website.
I even found an organization that many successful contractors in my industry join, and that org had its full member list, with contact info, on their website. You had to manually click one by one to get it, so I wrote a php scripts to scrape it. I'm not a pro at programming, so it probably took me almost as long to write that script as it would have taken to just manually copy and paste all ~1000 contacts. But atleast once done it was in an accessible format to have php blast the emails out, one every 30 seconds via a cron job, with customized name included.
You can usually buy these lists from organizations as well, by "joining" as a vendor.
What industry are you in?
